There are previously known techniques for employing arrays of cathode-ray tube ("CRT") displays in "video walls" and signage applications. Multiscreen displays employ an abutted array of substantially identical display devices that each display a subdivided portion of a total image such that together they display the total image. Because multiscreen displays require that each of the display devices be perceived as part of a whole large display device, it is important to make the boundaries between adjacent display devices appear as inconspicuous as possible. Unfortunately, the human eye is very sensitive to boundary discontinuities, making an acceptably "seamless" multiscreen display very difficult to produce.
This is especially true for arrays of CRT displays because of their curved face plates and nondisplayable borders. CRT projection displays eliminate some of the faceplate and border problems, but are typically heavy and deep because of the 48- to 60-inch-long light paths typically required to project an image on 40- to 52-inch screens. Stacking such CRT projection displays into a multiscreen array typically requires placing the lowermost displays on a stand and securing the individual display packages together with "trunk-style" latches. However, because latches on the innermost displays are not accessible, gravity is often depended on to hold a stack of displays together. The resulting multiscreen CRT display stack may be mechanically unstable, is limited to rear access to inner members of the stack, is typically 48- to 60-inches deep, requires service access space behind the rear of the stack, and is generally wasteful of commercially valuable floor space.
CRT-based multiscreen displays also have image stability and image matching problems, which could be mitigated by a digitally addressed, compact, lightweight display, such as the liquid crystal projection display described in "A 750-TV-Line-Resolution Projector Using 1.5-Megapixel a-Si TFT LC Modules," Takeuchi et al., Society for Information Display, SID 91 DIGEST, pp. 415-418. However, liquid crystal displays ("LCDs") have not been readily accepted for use in multiscreen display applications because they have projection lamp-induced luminance variations and liquid crystal display transfer function variations that make luminance matching and color balancing difficult among adjacent displays in an array. Fortunately, solutions to such luminance and color-matching problems are described in copending U.S. patent application Ser. No. 08/740,966, filed Nov. 5, 1996, for COLOR AND LUMINANCE CONTROL SYSTEM FOR LIQUID CRYSTAL PROJECTION DISPLAYS, which is assigned to the assignee of this application and incorporated herein by reference.
What is still needed is a mechanically stable, array-stackable display package having minimal depth and an integral stand that provides front and rear service access to internal modules when stacked in an array. Such a package would render displays serviceable and suitable for use in large screen and/or multiscreen display applications.